Prosthetic users typically spend more energy walking on their artificial feet than most people, because the devices cannot replicate the force of a living ankle pushing off the ground. Now researchers have created a new prosthetic foot that recaptures the mechanical energy between steps.
Test subjects who used a conventional prosthetic foot spent 23 percent more metabolic energy, as opposed to when they walked on two normal feet. One engineer likened the experience to walking with an extra 30 pounds weighing him down.
All the latest footwear engineering in your running sneakers might not mean a thing when it comes to preventing injuries. The latest barefoot running study in the journal Nature deployed 3-D infrared tracking to gauge the difference in foot strike between shod and shoeless runners, Scientific American reports. Here's a modern-day meme summation of the findings: "Shoes? You're doing it wrong."
Human running speeds top out near 28 mph, if the record-breaking feats of Jamaican speed demon Usain Bolt prove anything. But scientists say that the biological limits of human running could theoretically reach 35 or even 40 mph -- assuming that human muscle fibers could contract faster and allow people to pick up their pace.